1. Field of the Invention
The present invention relates to image pickup apparatuses, image pickup methods, image processing apparatuses, image processing methods, and image processing programs. In particular, the present invention relates to an image pickup apparatus, an image pickup method, an image processing apparatus, an image processing method, and an image processing program that have white balance functions.
2. Description of the Related Art
In recent years, digital image pickup apparatuses, such as digital still cameras and digital video cameras, have become increasingly used, and these products have become increasingly sophisticated. Accordingly, manufacturers of image pickup apparatuses want to increase the commercial values of their products by providing them with more advanced functions.
An auto white balance function is one of such image pickup apparatus functions. In the auto white balance function, an original color of white can be reproduced as white by setting the proportions of RGB (red, green, blue) uniformly in order to automatically adapt to a change in tint of a light source for a subject.
In general, an image pickup apparatus having an auto white balance function performs color control in which an achromatic color portion on a subject is extracted and set to be achromatic. In this control, since the color of the subject changes depending on light, a range of colors in the achromatic color portion under natural light is treated as an achromatic color detection range.
However, this control may mistakenly determine that a skin color is achromatic because a face's skin color is very close to the tint of the achromatic color portion under a low-color-temperature light source. In particular, this tendency is high when an image has a large skin color area. This results in a shift in white-balance-gain, thus causing the image to be blue.
Accordingly, a white-balance-gain setting method is known (see, for example, Japanese Unexamined Patent Application Publication No. 2003-189325). In this method, when a face is detected by detecting a face included in a picked-up image, by moving, a white-balance-evaluation-value acquisition area for setting a white-balance-gain to an area other than that of the face, a calculation of face portion white balance is prevented from being performed.